Some people will say to flush. I'm not from that camp. I would just feed plain water for awhile and then base nutes at half strength stopping around a week from harvest and then just plain water. I wouldn't do anything drastic like dumping gallons of water on it.
It doesn't matter what week the plant is. It will be done when it's done. The amount of weeks claimed by breeders is just a rough estimate. They might claim 11 weeks but it could take 15 weeks. Harvest based on bud maturity not some predetermined amount of time it's supposed to take. I don't even mark dates down anymore. I just grow my plants until they're ready. Doesn't matter if it's 8 or 12 weeks. They're done when they're done. Worrying about the stated amount of weeks causes many people to harvest too early and miss out on the quality that could have been had if they let the plant go until it was done instead of chopping on a certain date they marked on their calendar.
I would stop using the pH perfect for growing in soil. It's more for hydro and has a lower ph than what you want for soil. "When you use any Advanced Nutrient’s base nutrient, the pH Perfect® Technology inside automatically stabilizes and locks in your pH within the optimal range (called the ‘sweet spot’) of pH 5.5–6.3 – and keeps it there for one week". It's a little late now but in the future you might want to try a simple one part nutrient like MegaCrop. A lot of people seem to like it. It's easy and inexpensive. I've looked at the ingredients and it contains everything a plant needs.
The plant doesn't look that bad. You have a few weeks left. Just back off the nutes and let it finish. You should end up with some decent bud. It's not a perfect grow but much better than many I've seen. You'll figure it out.
Good luck.
